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Everything posted by YKSE

  1. Hi Dave, I've had two pairs of Maxbright, one with compression rings, and the other not. They all have three screws for each EP-holder. The binoviewer I bought new had only two screws attached to it, while the other 4 screws were in the cut-out in the box. Mechanical, the inner diameter of none-compression-ring pair feels a tiny bit tighter, optically, they were the same to my eyes, I ddin't find merging difficulty with any of them. I kept the the one with compression rings since none of my binoviewer EPs has under-cut, so a small cosmetic advantage with compresion rings.
  2. I'm glad you come to the conclusion. When I got C8 for some years ago, I did read quite a lot on CN, when Eddgie had numerous posts about the disadvantage of increase back focus with accessaries, therefore I haven't bother to add any external focuser to it. To my understanding, increase FL with narrower TFOV and possible vignetting with max TROV eyepieces are minor fault, the biggest one the spherical aberration correction is too far away from the optimal, which has major impact on image quality.
  3. I have it, a light-weight 2" 40mm-ish eyepiece, works great in all my scopes, enough ER for my glasses, very easy with eye placement. What I've gathered is that: it's a clone of TMB Paragon, it's phasing out by supplier (40mm TS paragon assumes to be the same clone, and sold out). My 120ED f7.5 is closest to your 130mmf7.7, 40mm Aero has quite tight stars in the edge, very good lateral colour(LC) control. Some other EP's around this focal lengthes: Panoptic 41mm: slightly better edge correction in your scope, much heavier and costly. Vixen 42mm LVW: slightly heavier, s
  4. Maybe I didn't use the words correctly. When typing "shine through", I was thinking of looking through an eyepiece, the right word here might should be shine at the lens(es), and look at the lens(es). Not shine nor look at side of a lens.
  5. I'd propose a simple method which might eliminate the guess work: Shine a flashlight through each of the lens(es), if you see two reflection spots, it's a singlet, three spots= doublet, four spots=tirplet.
  6. Nice one Marin I'm interested in reading more of your impression and measurement.
  7. Are you sure it's virtual image? My impression from high school is that you can't do anything to a virtual image, either relay or manipulate it at its position, since it's not there, and that's why it's called virtual, in contrary to "real image". OR?
  8. It's this one, with SC thread. https://www.firstlightoptics.com/adapters/baader-click-lock-2-for-celestron-meade-sct.html
  9. The test looks impressive with lots of optical measurement, but how much do the scores matter? It was discussed a year ago, I think it raised more questions than it answers:
  10. I have 4 zooms, Leica Asph, Baader Mark III, and a pair of Nikon 9-21mm, U'm a zoomholic if you like. Leica zoom has been my main DSO eyepiece with C8 for the last 3 years, almost all the small faint fuzzies. The convience of changing magnifications, the active zooming for threshold DSO made it much easier to detect. It's also used in 120ED or 80ED in backyard for quick session when there's a gap among clouds. Baader zoom has been used for PST, since Leica doesn't reach focus there, also used for mount alignment, also for family members and outreach. Nikon zooms are for binoviewe
  11. Well, standard SCT is a bit than a f10 newt, 8" sCT has FC slightly better than your 120f5, but none the less visible, it has coma corresponding a f5.4 newt (if my memory doesn't fail me), so you're going to see coma/FC in the scope in combination of other aberrations in the EPs. The field stop sharpness tests are more to have some idea wherearbout is your max pupil, if all EP have sharp field stops in SCT. If you have aperture stop-down in ST120, the field stop is cut by your eye pupil, which is not as clean cut as field stop in EPs, therefore it looks fuzzy.
  12. Interesting test Doug. As you've mentioned, these are quit long fl EPs for f5, so there may some other factors than EP showing here, such 1. FC of the scope, with 600mm fl, I'd expect noticeable FC from it, have you tried to identify that? 2. 36mm hyperion, espiecially 42mm superview, might give larger exit pupil than your max pupil, the result will be aperture stop-down with long focal ratio, the less good transmission you felt can be compound result of some 15% lower mag and aperture stop-down. 3. Have you tried these EPs in C8? How's the field stops look like in C8? all
  13. Sorry for the typo. it's my thick fingers, it should be "We". I'm not sure I've expressed the message clear, let me try to put it in another way With the same eyepiece in a scope, if you just go out from a well-lighted house/room, your eye pupil will be about 2-3mm, looking through the eyepiece, you may feel eye relief short or just right; after you stay out and avoid looking at direct light for, say half an hour, your eye pupil will get quite wider, presumably near your max eye pupil, looking through the eyepiece again, you're likely to feel the ER is longer than earlier. This is t
  14. Dave, A very interesting story and enjoyable as usual Let's keep our fingers crossed for more clear and steady nights.
  15. I'm glad you find Wiki as a good resource to get a first insight of questions, I certainly hope more should do it. TWe can, however, find more insight to any question deeper than Wiki can provide. I'm under impression that you have many posts about eye reliefs, what your experience of your perception of ER depending how dark-adapted your eye is?
  16. Eye relief (ER) is a recurrent topic here, not least by glass-wearers, many eyepieces do provide nominal ER, assuming the numbers are correct (not always the case), there're still other factors affecting the actual available ERs, such as recessed or concave eyelens etc, since ER is defined from eyelens center to eye ploint. There's an interesting aspect brought up in the other site, which might affecting the ER positively https://www.cloudynights.com/topic/561801-bargain-widefield-ep-performance-in-a-flatfield-scope/?p=7624593 Here's the illustration picture: The point
  17. admitting mistakes is the way to learn. Have great observing time.
  18. Read the online patent, you'll how the maintenensce fee pays to extend a patent: https://www.google.com/patents/US4482217 There're many unik eyepiece designs protected with patents, whether or not worth to apply for patents or keep the patent in effect, it's different business decisions, I'd guess.
  19. My bad, I forgot ASSA's recommendation was not in your quote.
  20. You got me confused In which way is mis-interpreting other's review like your own observations/preferences?
  21. Thanks stu, I've read that patent a couple of times through the years
  22. Where in the patent saying Televue plossls are not symmetrical?
  23. I wear glasses, still can see most the AFOV of 10mm BCO, 52° AFOV is a bit wider than SLV's 50°, can't see the drift-time issue? Wider AFOV is a way to have more observing time, there're other ways too, e.g. tracking mount/platform, or a quality zoom, much to the choice of observors.
  24. Google translation doesn't give the judgement "far, far behind"? Rather, it said 10mm BCO seemed to have better coatings to give impression of brighter image than 9mm BGO?
  25. "The last 9yrs"? was it a typo? I have the impression that there was a period of time without abbe orthos on the market before BCO came out in the end the 2012, and these Supper Abbe orthos came out some years after BCO, at least in TS's website which I visit regularly.
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